Fork assist



United States Patent [72] Inventor Donald W. Soper Cross St., Orland,Maine 04472 [211 App]. No. 834,189 v [22] Filed Apr. 18, 1969 [45]Patented Dec. 22, 1970 [54] FORK ASSIST 5 Claims, 3 Drawing Figs.

[52] U.S.C1 214/750, l93/35z2l4/84 [51] lnt.Cl. B66f9/l9 [50]FieldofSearch 214/750, 84; 193/35,42

[56] References Cited UNITED STATES PATENTS 3,019,930 2/1962 Allen t.2l4/75OX 3,168,205 2/1965 Green 214/84 Primary Examiner-Albert J. MakayABSTRACT: As an assist in moving the fork of a lift truck under the loadmore easily and properly positioned without damage to the fork or thecommodities constituting the load, an elongated flat surface wedgeguided for slight longitudinal movement in each of the tines, and rollerbearings arranged transversely of the wedge or wedges for sustaining theload as said rollers, embedded for half of their diameter in the wedge,are moved under the load by the said movement of the wedge which may beby hydraulic or other automatic means.

1 FORK Assrs'r SPECIFICATION The present invention, while relating tolift trucks in general, has more particular reference to trucksemploying forks in which load carrying tapered tines extending forwardfrom an upright body portion are forced under the commodity to be moved,particularly an unpalleted commodity, such maneuver of the fork oftendoing excessive damage not only to the tines in proper positioning themfor the lift but to the load itself and or the wrapping when the loadcomprises one or a number of individual packages.

The main object of the invention is to both ease the insertion of thetines under the load but also eliminate the possibility of damage suchas above enumerated.

Another object of the invention is, in the accomplishment of theaforesaid objective, the provision of means whereby, as the fork ismoved forward the load, instead of resting directly on the tines, willbe sustained and friction reduced by a series of transversely arrangedroller bearings brought into engagement with the under surface of theload and by a second series of like roller bearings in engagement withthe floor surface from which the load is to be lifted.

Still another object of the invention is the provision of an elongatedwedge slidable endwise in each of the tines and comprising the means inwhich the said roller bearings are journaled.

Yet a further object of the invention is the provision of an hydraulicsystem for controlling movement of the roller carrying wedge or wedges.

The accompanying drawing illustrating a preferred embodiment of theinvention is as follows:

FIG. I is a top plan view of the invention;

FIG. 2 is a view partly in side elevation and partly in section on theline 2-2 ofFIG. I;

FIG. 3 is an enlarged vertical section on the line 3-3 of FIG. 2.

Like numerals of reference indicate similar parts throughout thedifferent views.

At 1 there is shown the lower body portion of the fork of a lift truckwhich may be of standard make or any preferred construction. And,extending laterally forward from the fork portion 1 is a commoditysupporting member 2 generally decreasing in thickness toward its outerend. In this instance the member 2 represents one of a plurality oftines the free end 3 of which is chamferredas shown. Within the tine 2is an elongated chamber 4, the walls thereof providing a housing inwhich a wedge 5, flat faced the length and breadth of its top and bottomsurfaces, respectively, has a limited longitudinal movement forward andback, such movements being performed through the medium of any suitableoperatable means which, in this instance, is represented as a pump, apiston rod 6 in an hydraulic system not otherwise shown but which mayalso include the means for raising and lowering the fork, the piston rod6, its cylinder 7 and hose connection 8 also being housed within thechamber 4 in rear of the wedge 5.

Slot openings 9 and 10 in the tines 2 are opposed to the top and bottomsurfaces, respectively, of the wedge 5. For the slot 9 there is a seriesof transversely extending roller bearings 11, and, for the slot 10 thereis a like series of roller bearings 12. These bearings 11 and 12 aremounted in the sidewalls of the respective slots 9 and 10 and embedded,each for half its diameter, in the wedge 5. Sufficient clearance isallowed in assembly of parts that the rollers 11 and 12 are brought intoand out of contact respectively with the under surface of the load onthe fork and the flooring from which the load is lifted. The load, underwhich a fork is being moved, is indicated in phantom lines at 13 in FIG.2.

Iclaim:

1. In a lift truck the combination .with a fork including an uprightbody portion and a forwardly extending load supporting portion, thelatter having an elongated chamber, of a wedge slidabl mounted forlimited endwise movement in said chamber, suc chamber havlng slotopenings opposed to the top and bottom surfaces of said wedge, a seriesof transversely arranged roller bearings mounted in the sidewalls of thetop one of said slot openings, a second series of like roller bearingsmounted in the sidewalls of the bottom one of said slots, and means formoving said wedge forward and back whereby said first and second namedseries of rollers are respectively brought into and out of contact withthe under surface of the load on the fork and the flooring from whichthe load is lifted.

2. The combination according to claim 1 wherein the means for effectingthe longitudinal movement of said wedge is automatic in operation.

3. The combination according to claim 1 wherein a pump, in an hydraulicsystem for lifting and lowering the fork, is the means for controllingthe movement of said wedge.

4. The combination according to claim 1 wherein the rollers of both saidseries are embedded for half their diameter in respective slots in topand bottom faces of the wedge in which they are journaled 5. Thecombination according to claim 1 wherein the said load supportingportion is one of a plurality of tines.

